Conventionally, a variety of monitoring devices have been devised and some of them are already employed in applications including security, prevention of burglary, access management, no man bank, military purposes, toys, and industrial control for monitoring the appearance of foreign objects, human being or the like in a specific space (e.g., sensitive area). Typically, the monitoring devices are classified as detecting ones and sensing ones as detailed below.
As for detecting technique, it involves that a detecting member transmits signals in the form of or by means of laser, IR (infrared), ultrasonic waves, or radar to a receiving member. A signal is sent back to the detecting member from a receiver of the receiving member (i.e., target). The detecting member then analyzes the strength and/or phase lags of the signal or the like for obtaining data including direction, size, and distance of the receiving member by intensive calculation. The detecting member will respond accordingly thereafter.
As for sensing technique, it involves that radiation from a target (e.g., IR transmitted from a human being) due to temperature, or changes of environmental parameters (e.g., turbulence or differences of images taken by a camera) due to motion of the target can be sensed by a sensing member. Next, data including direction, size, and distance of the target can be obtained by intensive calculation.
However, both prior techniques suffered from several disadvantages. For example, it is only possible of determining whether there is a target, whether the target is in motion if the target exists, and imprecise data about motion of the target if the target moves. As for control, a user has to set system parameters by means of an input device (e.g., remote control, switch, or computer) prior to control. For example, techniques of employing computer to display digital images for monitoring targets in a specific environment have been devised recently. Also, such techniques have been widely employed in digital monitoring systems. However, it requires a user to set environmental parameters by means of computer. As such, it cannot obtain precise data about motion of the target or any other useful data about the target.
In addition, the provision of signal transmission and receiving devices in the detecting member not only may increase system complexity and cost but also may make an incorrect measurement. As a result, an erroneous result is obtained and precious power is consumed undesirably. As for sensing technique, it depends on reliable factors including ambient temperature, percentage of the human body being exposed, etc. Thus, its accuracy is low. Moreover, a specific input device is required for control purpose when either the detecting or the sensing technique is carried out. This will inevitably increase the equipment expenditure. In general, it is not applicable for ordinary situations.
Thus, it is desirable to combine a typical camera and an independent processing unit as a unitary system in which the camera is adapted to take pictures of a moving target in a specific space. Further, motion of the target can be determined by performing an image recognition process. As such, a corresponding operation is conducted in which an area defined by trace of the moving target is set as an image monitoring area. Alternatively, the area is employed to open, close, adjust, set, enable, or disable related equipment or an automatic system. Advantageously, it is possible of overcoming the above drawbacks of prior art by providing a fully automatic monitoring system without involvement of switches, keys, or any input devices.